S. S. Kiparisov

Reaction of titanium carbide with steel during sintering

ConclusionIt has been confirmed — qualitatively by x-ray structural analysis and metallographic examination and quantitatively by chemical and x-ray spectral analyses — that the components of a titanium-carbide-Kh6V3M-steel alloy react with each other during sintering and heat treatment.

Sintering of titanium-carbide-steel materials in various environments

ConclusionsA study was made of the wetting of titanium carbide by 5Kh6VM2 and Kh6V3M steels in a vacuum, argon, and hydrogen. The optimum compositions of steel binders were established ensuring good wetting of TiC in hydrogen. An investigation was carried out into the production of TiC-5Kh6VM2 and TiC-Kh6V3M materials by sintering in a vacuum, argon, and hydrogen. The properties of the resultant sintered materials were determined. It was found that good-quality nonporous specimens cannot be produced by sintering in hydrogen.

Structure formation in titanium-carbide-steel alloys during sintering (part II)

Conclusions1.The temperature at which a eutectic melt forms on TiC-R18 and TlC-R9K5 contact surfaces was determined and found to be 1130° C.2.A study was made, by the sessile drop technique, of the temperature dependence of the contact angles

Structure and properties of a self-lubricating material based on tungsten diselenide

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Structure formation in titanium carbide-steel alloys produced by the infiltration process

between titanium carbide and R18 and R9K5 steels.3.On the basis of an analysis of the thermodynamic stability of carbides and the strength of their chemical bonds as functions of carbide composition it is shown that the temperature of eutectic formation at a TiC-steel interface falls as a result of dissolution not of free carbon nor of TiC grains of composition close to stoichiometric but of TiC1-X.4.An examination is made of the liquid-phase sintering of ferro-TiC alloys in relation to the processes of dissolution and precipitation of carbides and to the disappearance of the eutectic as a result of its decarburization.

Effects of niobium carbide additions upon the production and properties of sintered high-speed steel

ConclusionsIt is demonstrated that titanium carbide powder can be obtained from titanium swarf. The following optimum parameters of carbidization in a vacuum corresponding to 0.013 Pa have been established: 1.5-h holding at a temperature of 1873°K; 0.5-h holding at 2273°K; 0.5-h comminution in a vibratory mill; and 0.5-h holding at 2273°K, The amount of oxygen in the titanium carbide powder produced was found to be less than that in the powder currently manufactured in the Soviet hard-metal industry.

Dependence of the properties of titanium carbide-steel materials upon the composition of the titanium carbide

Conclusions1.A study was made, by x-ray diffraction and electron probe microanalysis, of the phase composition of a WSe2—Ga/In composite material. The structure of the material was found to be composed of several chemical compounds, one of them corresponding to GaSe.2.An investigation of the antifriction properties of the composite material established that its coefficient of friction and wear decreased with increasing sliding speed and that its wear intensity was two orders of magnitude less than that of pure WSe2 (6 · 10−9 and 200 · 10−9, respectively).

Processing of W-Cr-V-Mo tool steel swarf by the powder metallurgy technique

Conclusions1.The density of a porous (powder) body being pressed is a function of the stress tensor, but is not uniquely related to the latters greatest component. The intensity of the compact densification process depends directly on the relative magnitude of the deviator component of the stress tensor.2.The decrease in the porosity of a material during pressing may follow any one of a multitude of possible trajectories within an OAB field representing, in a diagram of normal stress vs tangential stress, all combinations of stresses acting in a compact at which the latter experiences densification.3.The functions describing the relation between pressing pressure and compact density in the orthodox pressing techniques and the coefficients of these functions are determined by the character of the variation of the parameters K and γ with compact density, and are thus secondary relative to the latter functions.4.For the materials investigated the equationsK=Kγ and ϱ≈ϱ(γ) are approximately linear only in a relatively narrow range, of density variation (between γ≈60% and γ≈80%). This leads to the conclusion that the relation between pressure and density in pressing in rigid dies and in isostatic vessels varies in character during the whole densification process.